This application requests a renewal of support for the Hopkins Population Center (HPC) under the Research Infrastructure for Demographic and Behavioral Population Science Program as specified in RFA-HD-13- 007. The HPC is an interdisciplinary research center spanning four schools on two campuses of the Johns Hopkins University. It emphasizes innovative, interdisciplinary population research and support for new investigators. It has three signature themes: Its Poverty and Inequality theme supports research on the health and well-being of children from low- and moderate-income families. Its Sexual and Reproductive Health theme includes studies of the social context of sexually-transmitted infections and diseases and of contraceptive usage and demand. Its Family Demography and the Transition to Adulthood theme studies demographic trends in American family life and the determinants of the life-transitions that adolescents and young adults make as they start family lives and have children. The HPC is unique among population centers in that the great majority of its faculty associates are based at the Hopkins medical institutions: Public Health, Medicine, and Nursing. It nevertheless has strength in the School of Arts and Sciences, including the current HPC Director, Andrew Cherlin, a former president of the Population Association of America and the current chair of the Social Sciences and Population A Study Section at NIH. The HPC provides seed grants to promising projects that could lead to NIH grant applications; it supports junior faculty for developing and writing proposals; and it supports working groups that are developing innovative research projects. The HPC requests support for four cores. An Administrative Core will be responsible for the finances of the Center and will supervise activities, sponsor symposia, and perform other such tasks. A Computing Core will provide faculty associates with computing resources and information technology to fit their research needs. An Information Services Core will provide electronic information and bibliographic services. And a Developmental Infrastructure Core will encourage and develop research projects and proposals through pilot project grants, workshops, and other activities.